This invention relates generally to die cutting machines for making carton blanks, and in particular, to panel connection device for interconnecting a panel to a frame assembly for a lower blanking tool that supports carton scrap during a blanking operation in a die cutting machine.
In the manufacture of cartons, small sheets of paper material having specific profiles are cut out of larger sheets of paper material. These smaller sheets are known as carton blanks that, in turn, are formed into cartons and/or boxes. The blanks are formed during a process known as a blanking operation in a die cutting machine.
In a die cutting machine, the blanks are cut, but not removed from a large sheet of paper material. After the blanks have been cut, the sheet is moved downstream in the die cutting machine to a blanking station where the sheet is positioned over a frame assembly for support. The frame assembly includes an outer frame and an inner grid having large openings that correspond in size, in shape and in position to the profile of the carton blank previously cut. Below the frame is a mechanism for stacking the carton blanks.
At the blanking station, an upper tool is used in combination with the lower tool or frame assembly to knock the carton blanks from the sheet of paper material while holding the scrap material that surrounds the blanks. The upper tool has a support board that moves vertically up and down in the die cutting machine, and the support board typically has a plurality of stand-offs depending therefrom that hold pushers spaced beneath the board which in turn are used to push the carton blanks from the sheet through the lower tool or frame assembly. A plurality of presser assemblies are also mounted in the support board and depend therefrom to hold the scrap material against the lower tool or frame assembly during the blanking operation so that the blanks may be pushed from the sheet. A presser assembly typically includes a presser rail which is biased downwardly away from the support board by a spring so that the rail is positioned slightly below the pushers. As the upper tool is lowered, the presser rail engages the sheet of paper material first such that a scrap portion of the large sheet of material is secured between the presser rail and the frame. The upper tool then continues to be lowered such that the sheet of material engages the inner grid within the frame while at substantially the same time the pushers engage the carton blanks and knock the blanks out of the sheet of material and through the inner grid. The carton blanks then fall into a stacking mechanism below the frame where the blanks are stacked for further processing.
The lower tool used in the blanking operation is typically comprised of a steel or aluminum outer frame that supports an inner grid. The inner grid is typically comprised of a plurality of lengthwise and crosswise extending bars or panels. In order to secure the inner grid in place on the outer frame, the ends of each bar are typically screwed onto attachment pieces which, in turn, are mounted on the lengthwise and crosswise rails of the outer frame. Since the frame and grid support a sheet of paper material during the blanking operation, the grid must be configured to match or conform to the die cut in the sheet of paper material. In addition, the grid must be reconfigured whenever a different carton blank needs to be produced. Thus, unscrewing the inner grid from the outer frame oftentimes becomes very cumbersome and time consuming.
Therefore, it is a primary object and feature of the present invention to provide an improved panel connection device for interconnecting a panel to a frame assembly for a lower blanking tool of a carton die cutting machine.
It is a further object and feature of the present invention to provide a panel connection device for interconnecting a panel to a frame assembly for a lower blanking tool that allows for the panel to be easily attached and removed from the frame assembly.
It is a still further object and feature of the invention to provide a panel connection device for interconnecting a panel to a frame assembly for a lower blanking tool which is compatible with standard blanking operation machinery and which is relatively inexpensive.
In accordance with the present invention, a panel connection device is provided for attaching a panel of an inner grid to an outer frame for a lower blanking tool of carton die cutting machine. The panel has first and second opposite sides, a vertically extending end face, and a horizontally extending mounting pin projecting from the end face. The panel connection device includes a plate member defining a vertically extending inner face having a recess formed therein for receiving the mounting pin, an opposite vertically extending outer face, a horizontally extending upper face, an opposite horizontally extending lower face, a pair of opposite end faces, and a bore extending between an inner face and the outer face along an axis an acute angle to the outer face. A fastening structure extends into the recess of the plate member for retaining the mounting pin therein.
The recess in the inner face of the plate member is defined by first and second spaced vertically extending sidewalls and a recessed wall. The recessed wall has an upper face for supporting the mounting pin thereon. It is contemplated that the upper face of the recessed wall be generally arcuate. In addition, the first sidewall may include a shoulder. The shoulder defines a stop for engagement with the end face of the panel when the mounting pin is inserted in the recess in the inner face of the plate member. The fastening structure may include a set screw having a terminal end for engaging the mounting pin and retaining the mounting pin in the recess in the inner face of the plate member.
The acute angle of a bore that extends between the inner and outer faces of the plate member is in the range of 30 degrees and 80 degrees. Preferably, the acute angle is approximately 65 degrees. A fastening element may extend through the bore in the plate member. The fastening element is receivable in a corresponding slot in the outer frame to interconnect the plate member to the outer frame. The outer face of the plate member may include a lip that is engageable with a corresponding ledge along the outer frame to support the plate member thereon.
In accordance with a further aspect of the present invention, a panel connection device is provided for attaching a panel of an inner grid to an outer frame for a lower blanking tool of a carton die cutting machine. The panel connection device includes a plate member defining inner and outer faces. The plate member has a recess therein for receiving a portion of the panel and a bore extending between an inner face and the outer face along the axis at an acute angle to the outer face. A clamping structure extends into the recess in the plate member to retain a portion of the panel in the recess of the plate member. The clamping structure may include a set screw having a terminal end frame engaging the panel and retaining the portion of the panel in the recess in the plate member.
The recess formed in the inner face of the plate member is defined by first and second spaced vertically extending sidewalls and a recessed wall. The panel has first and second opposite sides, a vertically extending end face, and a horizontally extending mounting pin projecting from the end face. The recessed wall has a horizontal upper face for supporting the mounting pin thereon. The first sidewall includes a shoulder that defines a stop for engagement with the end face of the panel when the mounting pin is inserted into the recess in the inner face of the plate member. The outer face of the plate member may include an opening therein. The opening in the outer face communicates with the recess in the inner face of the plate member. The outer face may also include a lip that is engageable with the corresponding ledge along the outer frame to support the plate member thereon. A fastening element extends through the bore through the plate member and is receivable in a corresponding slot in the outer frame to interconnect the plate member to the outer frame. The acute angle of the bore extending between the inner face and the outer face of the plate member may be in a range of 30 degrees to 60 degrees. Preferably, the acute angle of the bore is approximately 65 degrees.
In accordance with a further aspect of the present invention, a frame assembly is provided for a lower blanking tool of a carton die cutting machine. The frame assembly includes a rigid outer frame and inner grid comprised of a plurality of panels. A plurality of clamps attach the panel to the outer frame. Each clamp includes a plate member and a fastening structure. The plate member defines a vertically extending inner face having a recess formed therein for receiving a portion of the panel and an opposite vertically extended outer face. The fastening structure extends into the recess of the plate member for retaining the portion of the panel therein.
The plate member of each clamp includes a bore extending between the inner face and the outer face thereof along an axis at an acute angle to the outer face of 30 degrees to 60 degrees. Preferably, the acute angle of the bore is approximately 65 degrees. The recessed formed in the inner face of the plate is defined by first and second spaced, vertically extending sidewalls and a recessed wall. The first sidewall includes a shoulder formed therein. The shoulder defines a stop for engagement with the panel when the portion of the panel is inserted into the recess of the plate member.